Due to the increasing number of people suffering from sleep disorders and the related overburdening of sleep laboratories dealing with these disorders, the examination and measurement of disturbances by means of mobile apparatuses has been shifted from the stationary sector to the ambulant sector. The patients are told how to deal with the sensors connected with these apparatuses and, after the measuring time, return the mobile recording apparatus to the doctor attending them; the doctor then analyzes the recorded measuring signals to subsequently make a diagnosis. This ambulant method is very inexpensive due to the high time requirements related with a measurement and, furthermore, the results are not influenced by performing the measurements in a surrounding which is strange for the patient.
Such a mobile recorder is described in EP-A-0 356 603. This recorder allows the recording of measuring signals by means of eight channels, their storage and subsequent analysis in a computer. In this connection, it is possible to program the recorder in different ways in order to reduce the number of measured data by a preselection and to limit the data to desired measuring data depending on the clinical picture or the purpose of the diagnosis. By this different programming, the measurement can be adapted to different frame conditions.
The measurement of different parameters for the detection of sleep disturbances is discussed in DE-A-41 38 702. The apparatus disclosed therein comprises sensors for detecting the heart potential, the respiratory and snoring sounds, the degree of oxygen saturation of the blood and the patient's body position. An analysis of the measured results allows the diagnosis of apnea. However, this analyzing apparatus is limited to only one application purpose, namely the detection of sleep disturbances (apnea) and, with the mentioned sensors, comprises analyzing instruments designed for this very purpose only. In particular, although sleep-related respiratory disturbances can be detected, the "side effects" related therewith, such as cardiac rhythm disturbances, cannot be detected.
With respect to the prior art, reference is also made to DE 92 04 190 U1, DE 32 48 222 A1, DE 39 21 784 A1, U.S. Pat. No. 3,734,086, DE 92 00 249 U1 and Kurz, Roland: "Medizinische MeBtechnik und Biosignalverarbeitung in der kardiologischen Diagnostik" [Medical Measuring Technique and Biosignal Processing in Cardiological Diagnostics], M.-G.-Schmitz-Verlag GieBen 1984, pages 122-129, ISBN 3-922 272-23-1.